Materials Around Us
Complete student notes with internal navigation, definitions, charts, classification tables, textbook solutions, HTML canvas diagrams and interactive quiz.
1. Chapter Overview
The chapter Materials Around Us explains that all objects around us are made up of materials such as paper, wood, cloth, glass, metal, plastic, clay and rubber. Materials have different properties, and these properties decide their uses.
2. Important Definitions Chart
| Term | Definition |
|---|---|
| Material | Any substance used to create or make an object. |
| Object | A thing made from one or more materials. |
| Classification | The method of arranging objects or materials into groups based on common properties. |
| Property | A feature or quality of a material, such as hardness, lustre, solubility, transparency, mass or volume. |
| Lustrous Materials | Materials that have a shiny surface. Metals usually show lustre. |
| Non-lustrous Materials | Materials that do not have a shiny surface. |
| Hard Materials | Materials that are difficult to compress or scratch. |
| Soft Materials | Materials that can be compressed or scratched easily. |
| Transparent Materials | Materials through which objects can be seen clearly. |
| Translucent Materials | Materials through which objects can be seen, but not clearly. |
| Opaque Materials | Materials through which objects cannot be seen at all. |
| Soluble Materials | Materials that dissolve completely in water. |
| Insoluble Materials | Materials that do not dissolve in water even after stirring. |
| Mass | The quantity of matter present in an object. Its common units are gram and kilogram. |
| Volume | The space occupied by matter. Its common units are litre and millilitre. |
| Matter | Anything that occupies space and has mass. |
| ORS | Oral Rehydration Solution, used to treat dehydration. It can be made by mixing sugar and salt in boiled and cooled water in correct amounts. |
3. Objects and the Materials They Are Made Of
Objects around us may be made from one material or a combination of different materials. A notebook is mainly made of paper, a pen may be made of plastic, metal and ink, and a tumbler may be made of steel, glass, plastic or clay.
| Object | Material / Materials Used | Reason for Using the Material |
|---|---|---|
| Notebook | Paper, cardboard | Paper is suitable for writing, and cardboard gives support. |
| Pen | Plastic, metal, ink | Different parts need different materials for writing and holding ink. |
| Tumbler | Steel, glass, plastic, clay | The material should be able to hold water. |
| Table | Wood, metal, plastic | The material should be hard and strong. |
| Water bottle | Plastic, steel, glass | The material should hold water and should not leak. |
| Cooking utensil | Steel, aluminium, iron, copper | The material should be hard and suitable for heating. |
4. How to Group Materials?
Objects and materials can be grouped on the basis of common properties such as shape, colour, hardness, softness, shine, dullness, transparency, solubility, mass and volume.
| Basis of Grouping | Groups Formed | Examples |
|---|---|---|
| Appearance | Lustrous and non-lustrous | Aluminium foil is lustrous; wood is non-lustrous. |
| Feel / Compression | Hard and soft | Brick is hard; pillow is soft. |
| Seeing through them | Transparent, translucent and opaque | Glass is transparent; frosted glass is translucent; wood is opaque. |
| Mixing with water | Soluble and insoluble | Sugar is soluble; sand is insoluble. |
| Weight-like comparison | Heavier and lighter | Pebbles are heavier than cotton for the same volume. |
| Use | Materials for writing, storage, cooking, construction and clothing | Paper for writing, metal for utensils, cloth for clothes. |
5. Different Properties of Materials
Materials look different and behave differently. Some are shiny, some are dull, some are hard, some are soft, some dissolve in water and some do not. These properties help us decide their uses.
Appearance
Materials may be shiny or dull, smooth or rough, colourful or colourless.
Hardness
Some materials are hard to compress or scratch, while others are soft.
Transparency
Some materials allow us to see clearly, partly or not at all.
Solubility
Some materials dissolve in water, while others remain unchanged.
Mass
Materials may be heavier or lighter depending on the amount of matter.
Volume
Materials occupy space. The space occupied is called volume.
6. Lustrous and Non-lustrous Materials
Materials that have shiny surfaces are called lustrous materials. Metals like iron, copper, zinc, aluminium and gold are usually lustrous. Materials that do not have a shiny surface are called non-lustrous materials.
| Type | Meaning | Examples | Important Point |
|---|---|---|---|
| Lustrous | Has a shiny surface | Iron, copper, aluminium, gold, steel | Freshly cut metal surfaces show more lustre. |
| Non-lustrous | Does not have a shiny surface | Paper, wood, rubber, jute, chalk | These materials usually look dull. |
7. Hard and Soft Materials
Materials that are difficult to compress or scratch are called hard materials. Materials that can be compressed or scratched easily are called soft materials.
| Object | Hard / Soft | Material | Reason |
|---|---|---|---|
| Brick | Hard | Baked clay | It cannot be compressed easily. |
| Water bottle | Usually hard | Plastic, steel or glass | It keeps its shape and holds water. |
| Pillow | Soft | Cloth, cotton or foam | It can be compressed easily. |
| Tumbler | Hard | Steel, glass, plastic or clay | It needs to hold liquid. |
| Table | Hard | Wood, metal or plastic | It must support weight. |
| Sweater | Soft | Wool or synthetic fibre | It can bend and fold easily. |
8. Transparent, Translucent and Opaque Materials
Materials can also be grouped according to how clearly we can see through them.
| Type of Material | Meaning | Examples |
|---|---|---|
| Transparent | Objects can be seen clearly through them. | Glass tumbler, window glass, water, air, cellophane paper |
| Translucent | Objects can be seen through them, but not clearly. | Butter paper, frosted glass, thin oily paper |
| Opaque | Objects cannot be seen through them. | Wooden board, eraser, metal, cardboard, wall, tree trunk |
9. Soluble and Insoluble Materials
Some materials disappear completely when mixed with water. They are called soluble materials. Some materials do not disappear even after stirring. They are called insoluble materials.
| Material | Observation in Water | Soluble / Insoluble |
|---|---|---|
| Sugar | Disappears completely after stirring | Soluble |
| Salt | Disappears completely after stirring | Soluble |
| Chalk powder | Does not disappear completely | Insoluble |
| Sand | Settles down and does not dissolve | Insoluble |
| Sawdust | Does not dissolve; may float | Insoluble |
Liquids and Gases in Water
Some liquids mix completely with water, while some form a separate layer. Some gases are also soluble in water. For example, oxygen gas dissolves in water and helps aquatic animals and plants survive.
10. Mass and Volume
Some objects are heavier and some are lighter. This difference is related to mass. The space occupied by something is called its volume.
| Property | Meaning | Common Units | Example |
|---|---|---|---|
| Mass | Quantity of matter present in an object | gram (g), kilogram (kg) | A cup containing pebbles has more mass than a similar cup containing cotton. |
| Volume | Space occupied by matter | litre (L), millilitre (mL), cubic metre (m3) | A 500 mL bottle contains 500 mL volume of water. |
Correct Way to Write Units
- Write 7 kg, not 7 kgs.
- Write 500 mL, not 500 ml or 500 mls.
- Write litre as L and millilitre as mL.
- Write 2 m3 for two cubic metres.
- Always leave a space between the number and the unit.
11. What is Matter?
Anything that occupies space and has mass is called matter. Water, sand, pebbles, air, cup, apple, wood, metal and plastic are all examples of matter.
| Example | Occupies Space? | Has Mass? | Is it Matter? |
|---|---|---|---|
| Water | Yes | Yes | Yes |
| Sand | Yes | Yes | Yes |
| Air | Yes | Yes | Yes |
| Apple | Yes | Yes | Yes |
| Light | No clear fixed space like material objects | No ordinary mass at this level | Not treated as matter in Class 6 |
12. Difference Between Important Topics
| Topic 1 | Topic 2 | Difference |
|---|---|---|
| Object | Material | An object is a thing we use. A material is the substance used to make the object. |
| Lustrous | Non-lustrous | Lustrous materials are shiny. Non-lustrous materials are dull. |
| Hard | Soft | Hard materials are difficult to compress or scratch. Soft materials can be compressed or scratched easily. |
| Transparent | Translucent | Transparent materials allow clear vision. Translucent materials allow partial or unclear vision. |
| Translucent | Opaque | Translucent materials allow unclear vision. Opaque materials do not allow vision through them. |
| Soluble | Insoluble | Soluble materials dissolve in water. Insoluble materials do not dissolve in water. |
| Mass | Volume | Mass tells the quantity of matter. Volume tells the space occupied by matter. |
| Material | Matter | Matter is anything that occupies space and has mass. Materials are types of matter used to make objects. |
13. Quick Revision Points
- Objects are made from a large variety of materials.
- An object can be made from one material or a combination of materials.
- Different materials can be used to make objects with similar functions.
- The method of arranging objects into groups is called classification.
- Materials are selected according to their properties and uses.
- Materials may be lustrous or non-lustrous.
- Materials may be hard or soft.
- Transparent materials allow us to see clearly through them.
- Translucent materials allow us to see through them, but not clearly.
- Opaque materials do not allow us to see through them.
- Some materials dissolve in water and are called soluble.
- Some materials do not dissolve in water and are called insoluble.
- Mass tells the quantity of matter.
- Volume is the space occupied by matter.
- Anything that occupies space and has mass is called matter.
14. Textbook Question Answers
1. Visit your kitchen and observe how edibles are organised. Suggest a better sorting method.
Answer: Kitchen items can be sorted into groups such as pulses, spices, grains, oils, snacks and beverages. A better sorting method is to keep similar items together in labelled transparent containers. Frequently used items should be kept in easily reachable places, while rarely used items can be kept separately.
2. Unscramble the letters and match with properties.
| Scrambled Word | Correct Word | Matched Property |
|---|---|---|
| T R E M A T | Matter | Occupies space and has mass |
| U L S B E L O | Soluble | Mixes completely in water |
| T N E R P A S N A R T | Transparent | Objects can be seen clearly through it |
| E R U S T L | Lustre | Shiny surface |
3. Why are storage containers in shops and homes usually transparent?
Answer: Transparent containers allow us to see the material kept inside without opening the container. This saves time, helps identify items easily and prevents unnecessary opening of containers.
4. State True or False and correct the false statements.
(i) Wood is translucent while glass is opaque. False. Wood is opaque while glass is transparent.
(ii) Aluminium foil has lustre while an eraser does not. True.
(iii) Sugar dissolves in water whereas sawdust does not. True.
(iv) An apple is matter because it occupies no space and has mass. False. An apple is matter because it occupies space and has mass.
5. Which chair materials fulfil the given properties the most?
| Desired Property | Suitable Materials | Reason |
|---|---|---|
| Hardness | Wood, iron, bamboo, cement, stone | These materials do not bend or shake easily. |
| Lightweight | Plastic, bamboo | These are easier to lift and move. |
| Does not feel very cold in winter | Wood, bamboo, plastic | These do not feel as cold as metal or stone. |
| Can be cleaned regularly and made to look new | Plastic, painted iron, polished wood | These can be wiped, washed or polished easily. |
6. Which materials will you choose for containers for food waste, broken glass and wastepaper?
| Waste Type | Suitable Container Material | Properties Needed |
|---|---|---|
| Food waste | Plastic or metal container with lid | Waterproof, washable, non-leaking, strong and easy to clean. |
| Broken glass | Thick plastic or metal container | Hard, strong, puncture-resistant and safe to handle. |
| Wastepaper | Cardboard, plastic or metal bin | Lightweight, dry, easy to move and large enough to hold paper. |
7. Air does not hinder us from seeing each other, but a wooden door does. Choose the correct option.
Answer: Air is transparent and the wooden door is opaque.
Correct option: (i) transparent, opaque
8. Mysterious materials X and Y: X is rigid and dissolves in water. Y changes shape easily and remains unchanged in water. Identify and justify.
Answer: Material X can be salt crystal or sugar crystal. It is hard because it feels rigid and does not change shape easily when pressed. It is soluble because it dissolves completely in water.
Material Y can be sponge, rubber or cotton. It is soft because it changes shape easily when pressed. It is insoluble because it remains unchanged in water.
9. Who am I? Identify on the basis of properties.
| Clue | Possible Answer |
|---|---|
| I have lustre. | Metal, aluminium foil, copper, iron or steel |
| I can be easily compressed. | Sponge, pillow, cotton or foam |
| I am hard and soluble in water. | Salt crystal or sugar crystal |
| You cannot see clearly through me. | Frosted glass or butter paper |
| I have mass and volume but you cannot see me. | Air |
Make your own: I am transparent and used in windows. Who am I? Glass.
10. Make soluble and insoluble pairs using vinegar, honey, mustard oil, water, glucose and wheat flour.
| Type of Pair | Pair | Observation |
|---|---|---|
| Soluble / Mixes completely | Glucose + water | Glucose dissolves in water. |
| Soluble / Mixes completely | Vinegar + water | Vinegar mixes with water. |
| Insoluble / Does not mix completely | Mustard oil + water | Mustard oil forms a separate layer. |
| Insoluble / Does not mix completely | Wheat flour + water | Wheat flour does not dissolve completely; it forms a suspension or dough-like mixture. |
15. Interactive Quiz
Choose the correct answer and click submit to check your score.
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